#include "maindialog.hpp"

#include <QCloseEvent>
#include <QDir>
#include <QMessageBox>
#include <QStringList>
#include <QTime>

#include <components/debug/debugging.hpp>
#include <components/debug/debuglog.hpp>
#include <components/files/configurationmanager.hpp>
#include <components/files/conversion.hpp>
#include <components/files/qtconfigpath.hpp>
#include <components/files/qtconversion.hpp>
#include <components/misc/helpviewer.hpp>
#include <components/misc/utf8qtextstream.hpp>
#include <components/settings/settings.hpp>
#include <components/version/version.hpp>

#include "datafilespage.hpp"
#include "graphicspage.hpp"
#include "importpage.hpp"
#include "settingspage.hpp"

namespace
{
    constexpr const char* toolBarStyle = "QToolBar { border: 0px; } QToolButton { min-width: 70px }";
}

using namespace Process;

void cfgError(const QString& title, const QString& msg)
{
    QMessageBox msgBox;
    msgBox.setWindowTitle(title);
    msgBox.setIcon(QMessageBox::Critical);
    msgBox.setStandardButtons(QMessageBox::Ok);
    msgBox.setText(msg);
    msgBox.exec();
}

Launcher::MainDialog::MainDialog(const Files::ConfigurationManager& configurationManager, QWidget* parent)
    : QMainWindow(parent)
    , mCfgMgr(configurationManager)
    , mGameSettings(mCfgMgr)
{
    setupUi(this);

    mGameInvoker = new ProcessInvoker();
    mWizardInvoker = new ProcessInvoker();

    connect(mWizardInvoker->getProcess(), &QProcess::started, this, &MainDialog::wizardStarted);

    connect(mWizardInvoker->getProcess(), qOverload<int, QProcess::ExitStatus>(&QProcess::finished), this,
        &MainDialog::wizardFinished);

    buttonBox->button(QDialogButtonBox::Close)->setText(tr("Close"));
    buttonBox->button(QDialogButtonBox::Ok)->setText(tr("Launch OpenMW"));
    buttonBox->button(QDialogButtonBox::Help)->setText(tr("Help"));

    buttonBox->button(QDialogButtonBox::Ok)->setMinimumWidth(160);

    // Order of buttons can be different on different setups,
    // so make sure that the Play button has a focus by default.
    buttonBox->button(QDialogButtonBox::Ok)->setFocus();

    connect(buttonBox, &QDialogButtonBox::rejected, this, &MainDialog::close);
    connect(buttonBox, &QDialogButtonBox::accepted, this, &MainDialog::play);
    connect(buttonBox, &QDialogButtonBox::helpRequested, this, &MainDialog::help);

    // Remove what's this? button
    setWindowFlags(this->windowFlags() & ~Qt::WindowContextHelpButtonHint);

    createIcons();

    QWidget* spacer = new QWidget();
    spacer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
    toolBar->addWidget(spacer);

    QLabel* logo = new QLabel(this);
    logo->setPixmap(QIcon(":/images/openmw-header.png").pixmap(QSize(294, 64)));
    toolBar->addWidget(logo);
    toolBar->setStyleSheet(toolBarStyle);
}

Launcher::MainDialog::~MainDialog()
{
    delete mGameInvoker;
    delete mWizardInvoker;
}

bool Launcher::MainDialog::event(QEvent* event)
{
    // Apply style sheet again if style was changed
    if (event->type() == QEvent::PaletteChange)
    {
        if (toolBar != nullptr)
            toolBar->setStyleSheet(toolBarStyle);
    }

    return QMainWindow::event(event);
}

void Launcher::MainDialog::createIcons()
{
    if (!QIcon::hasThemeIcon("document-new"))
        QIcon::setThemeName("fallback");

    connect(dataAction, &QAction::triggered, this, &MainDialog::enableDataPage);
    connect(graphicsAction, &QAction::triggered, this, &MainDialog::enableGraphicsPage);
    connect(settingsAction, &QAction::triggered, this, &MainDialog::enableSettingsPage);
    connect(importAction, &QAction::triggered, this, &MainDialog::enableImportPage);
}

void Launcher::MainDialog::createPages()
{
    // Avoid creating the widgets twice
    if (pagesWidget->count() != 0)
        return;

    mDataFilesPage = new DataFilesPage(mCfgMgr, mGameSettings, mLauncherSettings, this);
    mGraphicsPage = new GraphicsPage(this);
    mImportPage = new ImportPage(mCfgMgr, mGameSettings, mLauncherSettings, this);
    mSettingsPage = new SettingsPage(mGameSettings, this);

    // Add the pages to the stacked widget
    pagesWidget->addWidget(mDataFilesPage);
    pagesWidget->addWidget(mGraphicsPage);
    pagesWidget->addWidget(mSettingsPage);
    pagesWidget->addWidget(mImportPage);

    // Select the first page
    dataAction->setChecked(true);

    // Using Qt::QueuedConnection because signal is emitted in a subthread and slot is in the main thread
    connect(mDataFilesPage, &DataFilesPage::signalLoadedCellsChanged, mSettingsPage,
        &SettingsPage::slotLoadedCellsChanged, Qt::QueuedConnection);
}

Launcher::FirstRunDialogResult Launcher::MainDialog::showFirstRunDialog()
{
    if (!setupLauncherSettings())
        return FirstRunDialogResultFailure;

    // Dialog wizard and setup will fail if the config directory does not already exist
    const auto& userConfigDir = mCfgMgr.getUserConfigPath();
    if (!exists(userConfigDir))
    {
        std::error_code ec;
        if (!create_directories(userConfigDir, ec))
        {
            cfgError(tr("Error creating OpenMW configuration directory: code %0").arg(ec.value()),
                tr("<br><b>Could not create directory %0</b><br><br>"
                   "%1<br>")
                    .arg(Files::pathToQString(userConfigDir))
                    .arg(QString(ec.message().c_str())));
            return FirstRunDialogResultFailure;
        }
    }

    if (mLauncherSettings.isFirstRun())
    {
        QMessageBox msgBox;
        msgBox.setWindowTitle(tr("First run"));
        msgBox.setIcon(QMessageBox::Question);
        msgBox.setStandardButtons(QMessageBox::NoButton);
        msgBox.setText(
            tr("<html><head/><body><p><b>Welcome to OpenMW!</b></p>"
               "<p>It is recommended to run the Installation Wizard.</p>"
               "<p>The Wizard will let you select an existing Morrowind installation, "
               "or install Morrowind for OpenMW to use.</p></body></html>"));

        QAbstractButton* wizardButton
            = msgBox.addButton(tr("Run &Installation Wizard"), QMessageBox::AcceptRole); // ActionRole doesn't work?!
        QAbstractButton* skipButton = msgBox.addButton(tr("Skip"), QMessageBox::RejectRole);

        msgBox.exec();

        if (msgBox.clickedButton() == wizardButton)
        {
            if (mWizardInvoker->startProcess(QLatin1String("openmw-wizard"), false))
                return FirstRunDialogResultWizard;
        }
        else if (msgBox.clickedButton() == skipButton)
        {
            // Don't bother setting up absent game data.
            if (setup())
                return FirstRunDialogResultContinue;
        }
        return FirstRunDialogResultFailure;
    }

    if (!setup() || !setupGameData())
    {
        return FirstRunDialogResultFailure;
    }
    return FirstRunDialogResultContinue;
}

void Launcher::MainDialog::setVersionLabel()
{
    // Add version information to bottom of the window
    QString revision(QString::fromUtf8(Version::getCommitHash().data(), Version::getCommitHash().size()));
    QString tag(QString::fromUtf8(Version::getTagHash().data(), Version::getTagHash().size()));

    versionLabel->setTextInteractionFlags(Qt::TextSelectableByMouse);
    if (!Version::getVersion().empty() && (revision.isEmpty() || revision == tag))
        versionLabel->setText(
            tr("OpenMW %1 release").arg(QString::fromUtf8(Version::getVersion().data(), Version::getVersion().size())));
    else
        versionLabel->setText(tr("OpenMW development (%1)").arg(revision.left(10)));

    // Add the compile date and time
    auto compileDate = QLocale(QLocale::C).toDate(QString(__DATE__).simplified(), QLatin1String("MMM d yyyy"));
    auto compileTime = QLocale(QLocale::C).toTime(QString(__TIME__).simplified(), QLatin1String("hh:mm:ss"));
    versionLabel->setToolTip(tr("Compiled on %1 %2")
                                 .arg(QLocale::system().toString(compileDate, QLocale::LongFormat),
                                     QLocale::system().toString(compileTime, QLocale::ShortFormat)));
}

bool Launcher::MainDialog::setup()
{
    if (!setupGameSettings())
        return false;

    setVersionLabel();

    mLauncherSettings.setContentList(mGameSettings);

    if (!setupGraphicsSettings())
        return false;

    // Now create the pages as they need the settings
    createPages();

    // Call this so we can exit on SDL errors before mainwindow is shown
    if (!mGraphicsPage->loadSettings())
        return false;

    loadSettings();

    return true;
}

bool Launcher::MainDialog::reloadSettings()
{
    if (!setupLauncherSettings())
        return false;

    if (!setupGameSettings())
        return false;

    mLauncherSettings.setContentList(mGameSettings);

    if (!setupGraphicsSettings())
        return false;

    if (!mImportPage->loadSettings())
        return false;

    if (!mDataFilesPage->loadSettings())
        return false;

    if (!mGraphicsPage->loadSettings())
        return false;

    if (!mSettingsPage->loadSettings())
        return false;

    return true;
}

void Launcher::MainDialog::enableDataPage()
{
    pagesWidget->setCurrentIndex(0);
    mImportPage->resetProgressBar();
    dataAction->setChecked(true);
    graphicsAction->setChecked(false);
    importAction->setChecked(false);
    settingsAction->setChecked(false);
}

void Launcher::MainDialog::enableGraphicsPage()
{
    pagesWidget->setCurrentIndex(1);
    mImportPage->resetProgressBar();
    dataAction->setChecked(false);
    graphicsAction->setChecked(true);
    settingsAction->setChecked(false);
    importAction->setChecked(false);
}

void Launcher::MainDialog::enableSettingsPage()
{
    pagesWidget->setCurrentIndex(2);
    mImportPage->resetProgressBar();
    dataAction->setChecked(false);
    graphicsAction->setChecked(false);
    settingsAction->setChecked(true);
    importAction->setChecked(false);
}

void Launcher::MainDialog::enableImportPage()
{
    pagesWidget->setCurrentIndex(3);
    mImportPage->resetProgressBar();
    dataAction->setChecked(false);
    graphicsAction->setChecked(false);
    settingsAction->setChecked(false);
    importAction->setChecked(true);
}

bool Launcher::MainDialog::setupLauncherSettings()
{
    mLauncherSettings.clear();

    const QString path
        = Files::pathToQString(mCfgMgr.getUserConfigPath() / Config::LauncherSettings::sLauncherConfigFileName);

    if (!QFile::exists(path))
        return true;

    Log(Debug::Info) << "Loading config file: " << path.toUtf8().constData();

    QFile file(path);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        cfgError(tr("Error opening OpenMW configuration file"),
            tr("<br><b>Could not open %0 for reading:</b><br><br>%1<br><br>"
               "Please make sure you have the right permissions "
               "and try again.<br>")
                .arg(file.fileName())
                .arg(file.errorString()));
        return false;
    }

    QTextStream stream(&file);
    Misc::ensureUtf8Encoding(stream);

    mLauncherSettings.readFile(stream);

    return true;
}

bool Launcher::MainDialog::setupGameSettings()
{
    mGameSettings.clear();

    QFile file;

    auto loadFile = [&](const QString& path, bool (Config::GameSettings::*reader)(QTextStream&, const QString&, bool),
                        bool ignoreContent = false) -> std::optional<bool> {
        file.setFileName(path);
        if (file.exists())
        {
            if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
            {
                cfgError(tr("Error opening OpenMW configuration file"),
                    tr("<br><b>Could not open %0 for reading</b><br><br>"
                       "Please make sure you have the right permissions "
                       "and try again.<br>")
                        .arg(file.fileName()));
                return {};
            }
            QTextStream stream(&file);
            Misc::ensureUtf8Encoding(stream);

            (mGameSettings.*reader)(stream, QFileInfo(path).dir().path(), ignoreContent);
            file.close();
            return true;
        }
        return false;
    };

    // Load the user config file first, separately
    // So we can write it properly, uncontaminated
    if (!loadFile(Files::getUserConfigPathQString(mCfgMgr), &Config::GameSettings::readUserFile))
        return false;

    for (const auto& path : Files::getActiveConfigPathsQString(mCfgMgr))
    {
        Log(Debug::Info) << "Loading config file: " << path.toUtf8().constData();
        if (!loadFile(path, &Config::GameSettings::readFile))
            return false;
    }

    return true;
}

bool Launcher::MainDialog::setupGameData()
{
    bool foundData = false;

    // Check if the paths actually contain data files
    for (const auto& path3 : mGameSettings.getDataDirs())
    {
        QDir dir(path3.value);
        QStringList filters;
        filters << "*.esp"
                << "*.esm"
                << "*.omwgame"
                << "*.omwaddon";

        if (!dir.entryList(filters).isEmpty())
        {
            foundData = true;
            break;
        }
    }

    if (!foundData)
    {
        QMessageBox msgBox;
        msgBox.setWindowTitle(tr("Error detecting Morrowind installation"));
        msgBox.setIcon(QMessageBox::Warning);
        msgBox.setStandardButtons(QMessageBox::NoButton);
        msgBox.setText(
            tr("<br><b>Could not find the Data Files location</b><br><br>"
               "The directory containing the data files was not found."));

        QAbstractButton* wizardButton = msgBox.addButton(tr("Run &Installation Wizard..."), QMessageBox::ActionRole);
        QAbstractButton* skipButton = msgBox.addButton(tr("Skip"), QMessageBox::RejectRole);

        Q_UNUSED(skipButton); // Suppress compiler unused warning

        msgBox.exec();

        if (msgBox.clickedButton() == wizardButton)
        {
            if (!mWizardInvoker->startProcess(QLatin1String("openmw-wizard"), false))
                return false;
        }
    }

    return true;
}

bool Launcher::MainDialog::setupGraphicsSettings()
{
    Settings::Manager::clear(); // Ensure to clear previous settings in case we had already loaded settings.
    try
    {
        Settings::Manager::load(mCfgMgr);
        return true;
    }
    catch (std::exception& e)
    {
        cfgError(tr("Error reading OpenMW configuration files"),
            tr("<br>The problem may be due to an incomplete installation of OpenMW.<br>"
               "Reinstalling OpenMW may resolve the problem.<br>")
                + e.what());
        return false;
    }
}

void Launcher::MainDialog::loadSettings()
{
    const auto& mainWindow = mLauncherSettings.getMainWindow();
    resize(mainWindow.mWidth, mainWindow.mHeight);
    move(mainWindow.mPosX, mainWindow.mPosY);
}

void Launcher::MainDialog::saveSettings()
{
    mLauncherSettings.setMainWindow(Config::LauncherSettings::MainWindow{
        .mWidth = width(),
        .mHeight = height(),
        .mPosX = pos().x(),
        .mPosY = pos().y(),
    });
    mLauncherSettings.resetFirstRun();
}

bool Launcher::MainDialog::writeSettings()
{
    // Now write all config files
    saveSettings();
    mDataFilesPage->saveSettings();
    mGraphicsPage->saveSettings();
    mImportPage->saveSettings();
    mSettingsPage->saveSettings();

    const auto& userPath = mCfgMgr.getUserConfigPath();

    if (!exists(userPath))
    {
        std::error_code ec;
        if (!create_directories(userPath, ec))
        {
            cfgError(tr("Error creating OpenMW configuration directory: code %0").arg(ec.value()),
                tr("<br><b>Could not create directory %0</b><br><br>"
                   "%1<br>")
                    .arg(Files::pathToQString(userPath))
                    .arg(QString(ec.message().c_str())));
            return false;
        }
    }

    // Game settings
    QFile file(userPath / Files::openmwCfgFile);

    if (!file.open(QIODevice::ReadWrite | QIODevice::Text))
    {
        // File cannot be opened or created
        cfgError(tr("Error writing OpenMW configuration file"),
            tr("<br><b>Could not open or create %0 for writing</b><br><br>"
               "Please make sure you have the right permissions "
               "and try again.<br>")
                .arg(file.fileName()));
        return false;
    }

    mGameSettings.writeFileWithComments(file);
    file.close();

    // Graphics settings
    const auto settingsPath = mCfgMgr.getUserConfigPath() / "settings.cfg";
    try
    {
        Settings::Manager::saveUser(settingsPath);
    }
    catch (std::exception& e)
    {
        std::string msg = "<br><b>Error writing settings.cfg</b><br><br>" + Files::pathToUnicodeString(settingsPath)
            + "<br><br>" + e.what();
        cfgError(tr("Error writing user settings file"), tr(msg.c_str()));
        return false;
    }

    // Launcher settings
    file.setFileName(Files::pathToQString(userPath / Config::LauncherSettings::sLauncherConfigFileName));

    if (!file.open(QIODevice::ReadWrite | QIODevice::Text | QIODevice::Truncate))
    {
        // File cannot be opened or created
        cfgError(tr("Error writing Launcher configuration file"),
            tr("<br><b>Could not open or create %0 for writing</b><br><br>"
               "Please make sure you have the right permissions "
               "and try again.<br>")
                .arg(file.fileName()));
        return false;
    }

    QTextStream stream(&file);
    stream.setDevice(&file);
    Misc::ensureUtf8Encoding(stream);

    mLauncherSettings.writeFile(stream);
    file.close();

    return true;
}

void Launcher::MainDialog::closeEvent(QCloseEvent* event)
{
    writeSettings();
    event->accept();
}

void Launcher::MainDialog::wizardStarted()
{
    hide();
}

void Launcher::MainDialog::wizardFinished(int exitCode, QProcess::ExitStatus exitStatus)
{
    if (exitCode != 0 || exitStatus == QProcess::CrashExit)
        return qApp->quit();

    // HACK: Ensure the pages are created, else segfault
    setup();

    if (setupGameData() && reloadSettings())
        show();
}

void Launcher::MainDialog::play()
{
    if (!writeSettings())
        return qApp->quit();

    if (!mGameSettings.hasMaster())
    {
        QMessageBox msgBox;
        msgBox.setWindowTitle(tr("No game file selected"));
        msgBox.setIcon(QMessageBox::Warning);
        msgBox.setStandardButtons(QMessageBox::Ok);
        msgBox.setText(
            tr("<br><b>You do not have a game file selected.</b><br><br>"
               "OpenMW will not start without a game file selected.<br>"));
        msgBox.exec();
        return;
    }

    // Launch the game detached

    if (mGameInvoker->startProcess(QLatin1String("openmw"), true))
        return qApp->quit();
}

void Launcher::MainDialog::help()
{
    Misc::HelpViewer::openHelp("reference/index.html");
}
